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    <title>Document</title>
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    <!-- 这些属性要写到标签table 里面去 -->
    <table align="center" border="1" cellpadding="0" cellspacing="0" width="500" height="250">
        <tr><th>姓名</th>   <th>性别</th>   <th>年龄</th></tr>
        <tr><td>小明</td>   <td>男</td>   <td>18</td></tr>
        <tr><td>小红</td>   <td>女</td>   <td>19</td></tr>
        <tr><td>小白</td>   <td>女</td>   <td>21</td></tr>
        <tr><td>小光</td>   <td>男</td>   <td>23</td></tr>
    </table>
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